The video shows laser processed features and components that can be use for medical device applications.
FALSE: Glass can be machined without cracking. In this video, Mound Laser highlights a glass slide being laser machined. Using a 5W, 1025nm, 350fs pulse duration laser system, the micromachining engineers at Mound Laser are able to successfully machine a snowflake pattern out of 50 micron thick material without cracking the glass.
Typically, infrared wavelengths pass through glass with no absorption. However, the ultrafast femtosecond laser can machine the glass due to the high peak power and short pulse duration which enables a two photon absorption mechanism. This mechanism is driven by the large photon flux of the femtosecond laser which bombards the atomic lattice of the glass with so many photons that more than one is interacting with a given atom. This phenomenon allows photons to work together in driving off electrons leaving behind a positively charged atomic lattice which ends up in an explosion of positively charged particles. This entire reaction occurs on a timescale that is slower than the time it takes for heat to translate through the lattice. The lack of heat or athermal aspect of the process enables machining of the glass without thermal damage or cracking. The image of the snowflake at the end of the video shows the edge quality that can be achieved using this machining.
For the medical device industry, glass machining can be used for biofilters, encapsulation of electronics, minimally invasive products.
TRUE: In this video, we highlight the difference between using a nanosecond and femtosecond (ultrafast) pulse duration laser. When using the ultrafast laser, there is no heat input into the popcorn due to the 350 femtosecond pulse duration. This ultrafast pulse translates photon energy to the material’s electrons before there is time for this energy to be translated from the electrons to the lattice. This phenomenon is often referred to as athermal laser processing, and allows the Laser Applications Engineer to control the heat input parameter and not pop the popcorn. When using a nanosecond pulse duration laser, the heat input is higher and less controlled than an ultrafast laser system. With this laser, the heat input was sufficient to pop the popcorn.
The videos show the difference between two types of laser systems within Mound Laser’s micromachining department. The ultrafast femtosecond or picosecond laser systems are best suited for applications where material is sensitive to heat input such as bioabsorable material, polymers, nitinol and precious metals. These systems are capable of producing features down to 5 microns. Typical applications include stents, biofilters, or micro implants. The nanosecond pulse duration laser system is best suited for applications that require extensive amounts of precise material removal and have more tolerance for heat input. Mound Laser has 21 laser systems, and our Laser Applications Engineers will assist with selecting the right system for each customers’ applications.
TRUE: Mound Laser uses a football to demonstrate that surface textures can be recreated. In this example, the laser micromachining engineers at Mound Laser created the texture design based on the actual object, converted the design into a machining algorithm, and laser micromachined the surface texture of a football in copper material. To process this surface texture the engineer used an ultrafast laser system that has no heat input or recast on the part. The dimensions of this textured design are as followings: Depth: 0.005 mm deep, Width of football: 5 mm, Material thickness: 0.2 mm.
This example highlights the capability of laser micromachining to replicate any pattern or develop a new pattern for surface texturing. Laser surface texturing has been used on metals, ceramics, polymers, semiconductors, and composites. The process allows for improved tribological response, increased surface area, and improved or reduced biological adhesion. Mound Laser has expertise in nanosecond, femtosecond, and picosecond laser micromachining, and has access to 355nm, 532nm, and 1064nm wavelengths.
FALSE: Using a ND: YAG tube cutting system, Mound Laser demonstrates that using specific cut patterns in stainless steel hypotube will provide similar flexibility and performance as utilizing nitinol hypotube for the same application.
In our experiment, we show an application that is compatible with the aortic arch anatomy. Click the video below to view.
For some applications, the use of nitinol and stainless steel can be interchangeable. Often, stainless steel can be microcut to function in a similar manner as nitinol hypotube. Understanding the functional requirements of the hypotube are important in evaluating using stainless steel versus nitinol. Nitinol is typically chosen for its superelastic properties which enable the material to be navigated through tortuous anatomy. Because stainless steel does not have superelastic properties, it is often not considered as a material replacement for nitinol. However, using FEA analysis, Mound Laser has shown that in some cases when the superelastic properties of nitinol are not critical, a geometric cut pattern can be applied to stainless steel to provide equivalent product performance to nitinol applications. In these cases, companies can see a significant cost reduction in material without losing funtionality by substituting stainless steel in nitinol catheter products.
Another benefit of switching from nitinol to stainless steel is its increased weldability. If the product requires adhesive to be connected to another component, stainless steel hypotube may enable adhesive to be removed and replaced by laser welding. Through many prototype development projects, Mound Laser’s engineers have been able to substitute stainless steel hyptotube and experience no reduction in product performance. To find out if you application can benefit by switching materials, please contact Mound Laser.
TRUE: Using a 355nm Nd:YVO4 nanosecond laser micromachining system, Mound Laser shows that the laser can precisely cut through an orange peel . The micromachining system can selectively ablate the organic material to a controlled depth of 5 microns. In the video, the laser was able to ablate a basketball shape through the peel and stop before reaching the inside of the orange. The laser parameters were set just above the ablation threshold of the orange peel. If the processing were done significantly above the ablation threshold there would be a significant amount of charring due to the excessive heat input into the material. For commercial applications, this ablation accuracy enables micromachining features with tight tolerances. Applications include hole drilling, thin film processing, and layer striping. End application examples are minimally invasive instruments and implants, micro air vehicle components, and surface texturing.
In our experiment, we proved that you can peel an orange with the laser. To see the video, please click the below.
FALSE: Proper parameters are critical when athermally processing material. Specifically, the ablation threshold is key and varies by material. Understanding this parameter and how to process within the limit is critical to successful athermal processing.
As with any process, having the tool is only part of the solution. Mound Laser employs and trains scientists and engineers in the field of laser materials processing. The technical team uses these tools with a scientifically informed approach. The combination of state of the art laser tools and highly skilled scientists and engineers provide our customer with innovative solutions to their laser processing problems.
In the video below, two matches are used to disprove the laser myth. The video highlights how a change in laser settings can dramatically impact the effect of the laser on the material. Read more about ultrafast femtosecond laser processing on the laser micromachining page or press release page.